Telescopic display unit

ABSTRACT

To control the amount of shelf space to maintain a fully stocked display with fluctuating amounts of product, a telescopic shelving apparatus is provided. The telescopic display apparatus includes a housing with a pair of side walls and an elongate track member disposed at an angle to a horizontal plane on each wall. The apparatus further includes a plurality of angled sliders extending between the walls and coupled with one of the elongate track members. A plurality of adjustable shelves are each attached to a respective one of the angled sliders. A common control mechanism, along with the elongate track members, allows the sliders and their attached adjustable shelves to simultaneously extend or retract vertically as well as horizontally.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority from U.S. provisional patent application Ser. No. 62/027,987, filed Jul. 23, 2014, the contents of which are incorporated herein in their entirety.

FIELD OF THE INVENTION

This invention relates to a display unit. The display unit is equipped with shelves that may be adjusted in one or more dimensions relative to each other, as well as a mechanism for making such adjustments.

BACKGROUND OF THE INVENTION

Display units having multiple trays or shelves are well known. Such display units are generally provided with a frame, housing, or other construction to support the shelves. In such display units, multiple shelves may be pivotally attached to a frame, and the shelves may be provided with additional structures that support the shelves and their contents against the frame. Some display units further include shelves that may be adjusted along the horizontal or vertical axes.

Current display units present a problem as items are removed from the display surfaces. As fewer items are present on a shelf, the shelf begins to appear empty, which may be visually unappealing. Current display units do not provide a way to simultaneously adjust multiple shelves in both the horizontal and vertical directions using a single mechanism for the purpose of reducing the total amount of visual shelf space on a display unit in order to eliminate the unappealing aesthetic of an empty shelf. Accordingly, an adjustable display apparatus including a mechanism for the simultaneous adjustment of multiple shelves in the horizontal and vertical dimensions is desirable.

SUMMARY OF THE INVENTION

An adjustable display apparatus is provided. The adjustable display apparatus is provided with a housing, angled sliders, a plurality of shelves, an adjustment mechanism, and a bar linkage mechanism.

The housing is provided with a pair of side walls and a plurality of supports. Each of the side walls is provided with a slider track that is disposed upon each respective side wall at an angle relative to the horizontal plane. The track is provided with a slot or a cutout that may extend the entire length of the track. The supports project downward from the housing and support the display apparatus on the ground.

The angled sliders are elongate members that extend between the pair of side walls of the housing. Each of the angled sliders is provided with a first end, a second end, and a middle portion extending therebetween. The first end and second end of each angled slider is an elongate slider bar. The slider bar rests in the slider track, and therefore allows an angled slider to be supported by the two slider tracks between which it extends. Therefore, the sliders are disposed at an angle to the horizontal plane that is similar to the angle at which the slider track is positioned. This further allows for the angled sliders to slide up and down along the slider track at the predisposed angle. The slider bar is also provided with an aperture.

Each of the plurality of shelves has a top surface and a pair of side surfaces, or shelf end plates. The side surfaces or shelf end plates extend in a generally downward direction from the top surface of the shelf. Each of the shelf end plates is provided with an aperture. When a shelf is positioned in the housing, the aperture of a shelf end plate aligns with the aperture of a slider bar. A bolt or other fastener may then be used to pivotally affix the shelf to the slider bar. This arrangement allows the shelf to pivot about the point at which it is attached to the slider bar, as well travel along the slider track with the angled slider to which it is attached via the slider bar. Each shelf end plate is also provided with an additional support member that projects in a downward direction. This support member rests on the slider plate to which the shelf is attached when the shelf is in a downward pivoted position. When the shelf is in an upward pivoted position, the shelf is at an upward angle and the support member does not contact the slider plate.

The movement of the shelves along the slider track is controlled by an adjustment mechanism that may take the form of a rotatable crankshaft. In one embodiment, the adjustment mechanism includes a crank handle, although alternate methods of driving the adjustment mechanism may be used. For example, an electric motor may be used to drive the adjustment mechanism. In the present embodiment, the crank handle is attached to a bar that extends from the front of the display unit to approximately halfway into the display unit, where the bar s met by a tube. The bar fits inside of the tube and is capable of sliding in a telescoping motion into and out of the tube, as well as rotating with the tube about their shared longitudinal axis in a manner that causes the tube to rotate as well. The tube extends from where it first meets with the bar to the rear portion of the display unit. Here, the tube attaches to a threaded rod. A threaded nut is threaded onto the threaded rod between two rod bearings that are attached at either end of the threaded rod. When the crank handle is rotated, the bar rotates with and telescopes into the tube. The turning of the bar causes the threaded rod to rotate. This results in the threaded nut traveling along the threaded bar in a linear path as the rod is threaded into and out of the nut.

The bar linkage mechanism serves to couple the angled sliders and their attached shelves to the adjustment mechanism such that the adjustment mechanism is capable of adjusting the shelves. The bar linkage mechanism includes a pair of small bar linkages. One end of each of these small bar linkages attaches to either side of the threaded nut, such that there is one small bar linkage attached to the threaded nut on either side of the threaded rod along which the threaded nut may move. A common bar linkage also attaches to the other end of each of these small bar linkages, such that on either side of the threaded rod there is a small bar linkage attached to the threaded nut, with a common bar linkage further attached thereto. Attached to each of these common bar linkages is a plurality of additional connector linkages. The connector linkages couple the common bar linkage to each individual angled slider. At various points along the length of the common bar linkage, one end of a connector bar is attached, and the other end of the connector bar linkage is attached to one of the angled sliders. As this arrangement is the same on either side of the threaded rod, each angled slider is attached to two individual connector bars, with one connector bar positioned on either side of the adjustment mechanism. Each connector bar is attached to the common bar on its respective side of the adjustment apparatus, and the common bar attaches to the threaded nut via the small bar linkage.

Rotating the crank handle causes the threaded rod to rotate within the threaded nut, thereby moving the threaded nut in a linear direction along the threaded rod. If, for example, the threaded nut begins in a position closest to the rear of the display unit, and travels along a path towards the front of the display unit, the point of the common bar linkage that is attached to the small bar linkage follows this path, thereby causing one end of the common bar to travel towards the front of the unit, and the other end to be pivoted towards the rear of the unit. The common bar linkage is further attached to the adjustable display apparatus at a fixed pivot point about which this pivoting of the common bar linkage occurs as the threaded nut moves the common bar linkage. Therefore, all connector bar linkages that are attached to the common bar are also displaced towards the rear of the unit. As this occurs, the connector bar linkages pull the connected angled sliders and the shelves to which they are attached in the general direction that the connector bar linkages are travelling, causing the angled sliders to travel along the angled track that is disposed upon the sidewalls of the housing. This causes each of the plurality of shelves to travel in upward vertical and rearward horizontal directions. That is, the shelves slide horizontally under one another and vertically into one another, reducing the overall horizontal and vertical dimensions of the shelves. In this retracted position, there is reduced shelf surface area for displaying items.

In an alternative example, the display unit begins in the retracted position, and the crank handle is rotated such that the threaded nut moves from its position near the front of the display unit towards the rear of the display unit. The point of the common bar linkage that is attached to the small bar linkage follows this path, thereby causing one end of the common bar to travel towards the rear of the unit, and the other end to be pivoted towards the front of the unit. The common bar linkage pivots about its fixed pivot point, so all connector bar linkages that are attached to the common bar are also displaced towards the front of the unit. As this occurs, the connector bar linkages pull the connected angled sliders and the shelves to which they are attached in the general direction that they are travelling, causing the angled sliders to travel along the angled track that is disposed upon the sidewalls of the housing. This causes each of the plurality of shelves to travel in downward vertical and forward horizontal directions. That is, the shelves slide horizontally out from under one another and vertically out of one another, increasing the overall horizontal and vertical dimensions of the shelves. In this extended position, there is increased shelf surface area for displaying items.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an embodiment of a display apparatus of the present invention in the extended position;

FIG. 2 is a perspective view of an adjustable display apparatus in the retracted position;

FIG. 3 is a partially transparent side view of an adjustable display apparatus in the extended position;

FIG. 4 is a partially transparent side view of an adjustable display apparatus in the retracted position;

FIG. 5 is a partially transparent side view of an adjustable display apparatus with some of the shelves in an upward pivoted position;

FIG. 6 is a partially transparent top view of an adjustable display apparatus in the extended position;

FIG. 7 is a partially transparent top view of an adjustable display apparatus in the retracted position;

FIG. 8 is a partially transparent perspective view of an adjustable apparatus in the extended position;

FIGS. 8A-C are perspective views of an exemplary shelf for use with the present invention;

FIG. 8D is an enlarged transparent view of the circled area in FIG. 8;

FIG. 9 is a front perspective view of an adjustable display apparatus;

FIG. 10 is a perspective view of an alternate embodiment of an adjustable display apparatus in the extended position;

FIG. 11 is a perspective view of an alternate embodiment of an adjustable display apparatus in the retracted position.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring now to FIGS. 1 and 2, a perspective view of an adjustable display apparatus 10 is shown. The display apparatus is provided with a housing 20, which includes sidewalls 21 and support members 22. A plurality of adjustable shelves 40 are supported by the housing 20. In FIG. 1, the shelves 40 can be seen in an extended position. In FIG. 2, the shelves 40 can be seen in a retracted position. As shown, the adjustable shelves 40 are disposed in as rising steps from the front to the back of the housing. The adjustable display apparatus 10 may further include a fixed top shelf 12 disposed at the rear of the housing. Each adjustable shelf 40 steps down from the fixed top shelf, being located horizontally forward of and vertically below the next adjacent shelf 40 or 12. A crank handle 51 serves to adjust the positioning of the shelves 40.

Referring now to FIGS. 3, 4, and 5, a partially transparent side view of an adjustable display apparatus 10 is shown. A slider track 23 is mounted at an angle relative to a horizontal plane on or in each of sidewalls 21 of housing 20. Elongate slider bars 31 at the ends of angled sliders engage a slot 24 that is provided in slider track 23 to allow for support of the angled sliders and for adjustment of the adjustable display apparatus 10. This arrangement is more clearly shown in FIGS. 8 and 8D. Shelves 40 are disposed between the sidewalls 21 of the housing 20. Each of the shelves 40 are provided with a generally horizontal top surface 41, downwardly extending side surfaces 42, and a downwardly extending front surface 46. Side surface 42 may further be provided with a support projection 44 and an aperture 43. When the shelves 40 are disposed between the sidewalls 21 of the housing 20, a fastener 45 pivotally couples the aperture 43 of each shelf to an aperture 32 that is provided in corresponding elongate slider bar 31. This allows the shelf 40 to move along the slider track 23 with the elongate slider bar 31, as well as to pivot about the fastener 45.

FIG. 3 shows the shelves 40 in the extended position, wherein the vertical distances between the top surfaces 41 of shelves 40, as well as the horizontal distances between the front surfaces 46 of shelves 40, are at first distances. FIG. 4 shows the shelves 40 in the retracted position, wherein the vertical distances between the top surfaces 41 of shelves 40, as well as the horizontal distances between the front surfaces 46 of shelves 40, are at reduced values. As the shelves are retracted, the shelves 40 increasingly overlap each other. Each shelf 40 may have an upwardly extending rear surface 47 to prevent product from rolling off the back of each shelf. As shown in FIG. 4, the front surface of one shelf overlaps the rear surface of the next lower shelf as the shelves are retracted. FIG. 5 shows the shelves 40 pivoted to an upward position about the connection between aperture 43 of side surface 42 and aperture 32 of elongate slider bar 31.

As will be clear to those of skill in the art, the slider track 23 may be angled relative to horizontal and various angles depending on the desired vertical spacing of the shelves 40. In some embodiments, the slider track is angled in the range of 10 to 45 degrees.

Referring now to FIGS. 6 and 7, a partially transparent top view of an adjustable display apparatus 10 is provided. The sidewalls 21 of the housing 20 are provided with slider tracks 23. Both ends of angled sliders 30 are provided with elongate slider bars 31 that engage slider track 23 such that angled sliders 30 may slide along the slider tracks 23. The sliding motion of the angled sliders 30 along slider tracks 23 is facilitated by adjustment mechanism 50. Adjustment mechanism 50 includes a crank handle 51 that is coupled to bar 52. As can bee seen in FIG. 6, bar 52 extends into display apparatus 10, where it is met by tube 53. Bar 52 is at least partially inserted into tube 53 such that the bar 52 may telescope in and out of the tube 53. Furthermore, rotation of crank handle 51 causes rotation of the bar 52 about its longitudinal axis. As the bar 52 is inserted into the tube 53, rotation of the bar 52 also causes rotation of the tube 53 about its longitudinal axis. In this manner, rotation of the crank handle 51 causes both the bar 52 and tube 53 to rotate about their shared longitudinal axis as the bar 52 telescopes within the tube 53.

The end of the tube 53 into which the bar 52 is not inserted is attached to a threaded rod 54. Threaded rod 54 is inserted into a threaded nut 55, which may be a high density plastic linear nut. As the rotation of the crank handle 51 causes the rotation of the bar 52 and tube 53, threaded rod 54 also rotates, causing the threaded nut 55 to travel in a linear path along the threaded rod 54. That is, when the crank handle 51 is rotated in one direction, the threaded nut 55 travels a linear path along the threaded rod 54 towards the front of the adjustable display apparatus 10. When the crank handle 51 is rotated in the opposite direction, the threaded nut 55 travels a linear path along the threaded rod 54 towards the rear of the adjustable display apparatus 10. The movement of the threaded nut 55 along the threaded rod 54 is limited by rod bearings 56.

Threaded nut 55 is attached to a bar linkage mechanism 60. The bar linkage mechanism includes short bar linkages 61, common bar linkages 62, and connecting bar linkages 63. Short bar linkages 61 are coupled at one end to the threaded nut 55. At their other end, the short bar linkages 61 are coupled to one end of a common bar linkage 62. A plurality of connecting bar linkages 63 are attached at one of each of their respective ends to the common bar linkage 62. That is, one end of each of the connecting bar linkages 63 is attached at a different location along the length of the common bar linkage 62. The other end of each of the connecting bar linkages 63 is attached to one of the angled sliders 30. The connecting bar linkages 63 may be of different sizes. For example, the connecting bar linkages 63 that are closest to the sidewalls 21 of the housing 20 may be the longest connecting bar linkages 63, such that these connecting bar linkages 63 are attached at one end to a common bar linkage 62 at the end of the common bar linkage 62 that is not attached to the small bar linkage 61. As this connecting bar linkage 63 is the longest, its other end may be attached to the angled slider 30 that is nearest to the front of the adjustable display apparatus 10. As an additional example, the connecting bar linkages 63 that are closest to the adjustment mechanism 50 may be the shortest connecting bar linkages 63, such that these connecting bar linkages 63 are attached at one end to a common bar linkage 62. The other end of these connecting bar linkages 63 may be attached to the angled slider 30 that is nearest to the rear of the adjustable display apparatus 10. The attachment of the various components of the bar linkage mechanism 60 may be achieved by the use of fasteners 64.

In one mode of adjustment of the adjustable display apparatus 10, the threaded nut 55 travels in a linear direction towards the front of the adjustable display apparatus 10. This causes the small bar linkages 61, which are attached to the threaded nut 55, to be pulled in the direction of travel of the threaded nut 55. As the small bar linkages 61 are pulled in this direction, they pull the end of the common bar 62, to which the small bar linkages 61 are attached, in the same direction towards the front of the adjustable display apparatus 10. As this end of the common bar 62 is pulled toward the front of the display apparatus 10, the common bar 62 pivots about fixed pivot point 65. That is, the end of the common bar 62 that is attached to the small bar linkage 61 pivots toward the front of the adjustable display apparatus 10, while the end of the common bar 62 that is not attached to the small bar linkage 61 pivots toward the rear of the adjustable display apparatus 10. As the common bar 62 pivots about the fixed pivot point 65, the connecting bar linkages 63 that are each attached at one of their respective ends to the common bar 62 follow the end of the common bar 62 that is not attached to the small bar linkage 61. Therefore, the connecting bar linkages 63 travel toward the rear of the adjustable display apparatus 10. Because the common bar 62 pivots about the fixed pivot point 65, the connecting bar 63 that is attached to the end of the common bar 62 travels the greatest physical distance. The closer to the fixed pivot point 65 a connecting bar 63 is attached to the common bar 62, the less physical distance it travels. As the connecting bars 63 move, the ends of the connecting bars 63 that are attached to the angled sliders 30 each pull the angled slider 30 to which they are respectively attached toward the rear of the adjustable display apparatus 10. This causes the slider bars 31 to travel along the slider tracks 23 in both an upward and rearward direction. The distance that a slider bar 31 travels along the slider tracks 23 will be equal to the distance that the connecting bar 63 to which it is attached travels. Therefore, both the vertical and horizontal distances between the individual shelves 40 attached to a respective angled slider 30 are decreased, but the distance that each individual shelf 40 moves will be different. This leads to an overall decrease in the area of the top surface 41 of a shelf 40 that is available for use. However, because each individual shelf 40 travels a different distance, the area of the top surface 41 of a shelf 40 that is available may be kept constant between the individual shelves 40.

In another mode of adjustment of the adjustable display apparatus 10, the threaded nut 55 travels in a linear direction towards the rear of the adjustable display apparatus 10. This causes the small bar linkages 61, which are attached to the threaded nut 55, to be pulled in the direction of travel of the threaded nut 55. As the small bar linkages 61 are pulled in this direction, they pull the end of the common bar 62, to which the small bar linkages 61 are attached, in the same direction towards the rear of the adjustable display apparatus 10. As this end of the common bar 62 is pulled in this direction, the common bar 62 pivots about the fixed pivot point 65. That is, the end of the common bar 62 that is attached to the small bar linkage 61 pivots toward the rear of the adjustable display apparatus 10, while the end of the common bar 62 that is not attached to the small bar linkage 61 pivots toward the front of the adjustable display mechanism 10. As the common bar 62 pivots about the fixed pivot point 65, the connecting bar linkages 63 that are each attached at one of their respective ends to the common bar 62 follow the end of the common bar 62 that is not attached to the small bar linkage 61. Therefore, the connecting bar linkages 63 travel toward the front of the adjustable display apparatus 10. As this occurs, the ends of the connecting bars 63 that are attached to the angled sliders 30 each push the angled slider 30 to which they are respectively attached toward the front of the adjustable display apparatus 10. This causes the slider bars 31 to travel along the slider track 23 in both a downward and forward direction. Therefore, both the vertical and horizontal distances between the individual shelves 40 attached to a respective angled slider 30 are increased. This leads to an overall increase in the area of the top surface 41 of a shelf 40 that is available for use. In this mode of adjustment, the distances moved by the individual shelves 40 differ in the same manner that they do when the adjustable display apparatus 10 is adjusted to allow for an overall decrease in shelf space, as previously described. Similarly, this mode of adjustment also allows for the available area of the top surface 41 of a shelf 40 to be kept constant between the individual shelves 40, even as the overall available shelf space is increased.

Referring now to FIGS. 8A-C, perspective views of a shelf 40 of an adjustable display unit 10 are provided. FIG. 8A is a perspective view of a shelf 40 in an upward pivoted position. The side surface 42 and front surface 46 of shelf 40 are visible, as well as the support member 44 of the side surface 42. The rear surface 47 is also shown in the Figures. Additionally, the angled slider 30 and the elongate slider bars 31 attached thereto are shown. Fastener 45 that attaches the side surface 42 of the shelf 40 to the elongate slider bar 31 of the angled slider 30 is also visible. This attachment serves as the pivot point for the pivoting motion of the shelf 40 with relation to the angled slider 30. FIG. 8B is a transparent perspective view of the shelf 40 in a downward pivoted position. The support member 44 of the side surface 42 engages the angled slider 30 in this position. FIG. 8C is a perspective view of the shelf 40 in the downward position. The top surface 41, side surface 42, front surface 46, and rear surface 47 of the shelf 40 are visible. The elongate slider bar 31 is also shown.

Referring now to FIG. 9, a front perspective view of an adjustable display unit 10 is provided. The housing 20 is further provided with sidewalls 21 and support members 22. The shelves 40 extend between the sidewalls 21.

Referring now to FIGS. 10 and 11, perspective views of alternative embodiments of an adjustable display apparatus 10 are provided. The adjustable display apparatuses 10 shown in FIGS. 10 and 11 are substantially similar to those previously described, with the added feature of additional shelving 70. In FIG. 10, an adjustable display apparatus 10 in the extended position is shown, with one additional shelf 70 extending from the front of the adjustable display apparatus 10. In FIG. 11, an adjustable display apparatus in the retracted position is shown, with two additional shelves 70 extending from the front of adjustable display apparatus 10. The additional shelves are provided adjacent the front of the housing and below the adjustable shelves. The additional shelves may be horizontally slidable from a retracted position where they do not extend beyond the front of the housing to an extended position where they extend from the front of the housing.

The present invention provides an adjustable display apparatus with shelves that are simultaneously adjustable in the vertical and horizontal directions. A slider track that is provided on the housing of the apparatus engages angled sliders onto which the shelves are attached. An adjustment mechanism causes a bar linkage assembly that is attached to the angled sliders to pivot about a fixed point. This pivotal movement slides the angled sliders and the shelves attached thereto along the angled track. As the shelves slide along the track, the total available shelf area of the storage unit may be increased or decreased to a desired amount. Thus, the available shelf area may be adjusted to accommodate the volume of items that need to be displayed.

As will be clear to those of skill in the art, the herein described embodiments of the present invention may be altered in various ways without departing from the scope or teaching of the present invention. It is the following claims, including all equivalents, which define the scope of the invention. 

We claim:
 1. An adjustable display apparatus comprising: a housing; a first adjustable shelf and a second adjustable shelf each supported by the housing, wherein the first adjustable shelf has a vertical and a horizontal distance from the second adjustable shelf; an adjustment mechanism operable to simultaneously displace both of the adjustable shelves along a linear path relative to the housing such that both the vertical distance and the horizontal distance between the first adjustable shelf and the second adjustable shelf are increased or decreased in a coordinated manner.
 2. An adjustable display apparatus according to claim 1, wherein each of the adjustable shelves has a top surface, downwardly extending front surface and an upwardly extending rear surface, the front surface of the second adjustable shelf overlapping the rear surface of the first adjustable shelf when the adjustable shelves are displaced to a retracted position.
 3. An adjustable display apparatus according to claim 2, wherein the front surface and rear surface of each adjustable shelf are each generally perpendicular to the top surface.
 4. An adjustable display apparatus according to claim 1, further comprising a fixed top shelf disposed above the second adjustable shelf.
 5. An adjustable display apparatus according to claim 1, wherein the housing includes a pair of side walls, each of the pair of side walls provided with an elongate track positioned at an angle to a horizontal plane, the elongate track provided with an elongate slot.
 6. An adjustable display apparatus according to claim 5, further comprising: a first and a second angled slider extending between the pair of side walls, each of the angled sliders having a first end, a second end, and a mid-portion therebetween, each of the first end and the second end being an elongate bar engaging the elongate slot of the elongate track member, the elongate bar provided with an aperture; each of the adjustable shelves having a top surface and a pair of side surfaces, each of the pair of side surfaces provided with a support projection and an aperture, the aperture pivotally coupled to the aperture of the elongate bar such that each of the adjustable shelves is pivotally coupled to a respective one of the angled sliders; and a bar linkage mechanism coupling the angled sliders to the adjustment mechanism, the bar linkage mechanism having a plurality of connecting bar linkages, each of the connecting bar linkages being coupled to one of the angled sliders.
 7. An adjustable display apparatus according to claim 6, wherein each of the side surface of the adjustable shelves extends downwardly from the respective top surface.
 8. An adjustable display apparatus according to claim 6, wherein the adjustment mechanism includes a rotatable crankshaft.
 9. An adjustable display apparatus according to claim 8, wherein the rotatable crankshaft is a telescoping crankshaft.
 10. An adjustable display apparatus according to claim 6, wherein: the bar linkage mechanism further includes a pair of common bar linkages and a pair of small bar linkages; each of the pair of common bar linkages has a pivot point; each of the connecting bar linkages is coupled to one of the pair of common bar linkages; and each of the pair of small bar linkages is coupled to one of the pair of common bar linkages and further coupled to the rotatable shaft.
 11. An adjustable display apparatus according to claim 10, wherein: the adjustment mechanism further includes a threaded rod and a threaded nut; the rotatable crankshaft is fixed to the threaded rod, the threaded rod disposed within the threaded nut; and the rotation of the rotatable shaft causes rotation of the threaded rod within the threaded nut such that the threaded nut is displaced on a linear path along the threaded rod.
 12. An adjustable display apparatus according to claim 11, wherein when the threaded nut is displaced on the linear path along the threaded rod, each of the pair of common bar linkages is pivoted such that each of the plurality of connecting bar linkages is operable to displace each of the angled sliders in a direction opposite to the threaded nut.
 13. An adjustable display apparatus according to claim 6, further comprising: at least a third angled slider extending between the pair of side walls; at least a third adjustable shelf pivotally coupled to the third angled slider; wherein the third angled slider is coupled to the adjustment mechanism by the bar linkage mechanism.
 14. An adjustable display apparatus according to claim 1, further comprising at least one horizontally adjustable shelf disposed below the first and second adjustable shelves, the at least one horizontally adjustable shelf having a retracted position wherein it does not extend from the housing and an extended position wherein it extends from a front of the housing. 